Removing the avahi-daemon on Ubuntu

Avahi is the open-source implementation of Zeroconf, used for automatic management of networks without any centralized configuration. Generally, Avahi is only useful in small local networks (such as a home LAN).

The avahi-daemon process handles mDNS, which is used for name resolution and service discovery within the local network. If you don't need its functions, Avahi can be safely removed.

• Local name resolution – allows you to reach the computer by a hostname.local name without any centralized configuration. Since your server most likely has a DNS name, this function is unnecessary.

• Service discovery – allows programs to find and advertise running services (for example, to allow listing all SSH or PulseAudio servers in the LAN). This is convenient on a home network, but entirely useless for a datacenter-hosted server. This too can be safely removed.

(Other Avahi components, which are inactive on your server, are avahi-autoipd for RFC 3927 and avahi-dnsconfd for discovery of unicast-DNS servers.)

sudo apt-get purge avahi-daemon

To merely disable:

sudo systemctl stop avahi-daemon
sudo systemctl disable avahi-daemon